Formation of multisegmented plated through holes

ABSTRACT

A method and structure relating to multisegmented plated through holes. A substrate includes a dielectric layer sandwiched between a first laminate layer and a second laminate layer. A through hole is formed through the substrate. The through hole passes through nonplatable dielectric material within the dielectric layer. As a result, subsequent seeding and electroplating of the through hole results in a conductive metal plating forming at a wall of the through hole on a segment of the first laminate layer and on a segment of the second laminate layer, but not on the nonplatable dielectric material of the dielectric layer. Thus, the conductive metal plating is not continuous from the first laminate layer to the second laminate layer.

BACKGROUND OF THE INVENTION

[0001] 1. Technical Field

[0002] The present invention relates to plated through holes and moreparticularly to a method and structure for forming multisegmented platedthrough holes.

[0003] 2. Related Art

[0004] A plated through hole (PTH) in a printed circuit board (PCB)provides electrical communication between a first electricallyconductive structure electrically coupled to a first portion of the PTHand a second electrically conductive structure electrically coupled to asecond portion of the PTH. Unfortunately, constraining the electricalcoupling of such conductive structure to the first and second portionsof the PTH limits the wiring density that can be achieved in the PCB.

[0005] There is a need to utilize a PTH in a substrate in a manner thatfacilitates increased wiring density in the PCB.

SUMMARY OF THE INVENTION

[0006] The present invention provides a method for forming at least onemultisegmented plated through hole (PTH) in a substrate, comprising thesteps of:

[0007] providing a first laminate having a dielectric layer and a secondlaminate having a dielectric layer;

[0008] forming a first selective plate core (SPC) by sandwiching adielectric layer between a first metal layer and a second metal layer,wherein the dielectric layer of the first SPC includes a nonplatabledielectric material;

[0009] forming the substrate by sandwiching the first SPC between thefirst laminate and the second laminate;

[0010] forming a first through hole through the substrate; and

[0011] metalizing a wall of the first through hole to form a first PTHof the at least one PTH, resulting in a metal plating on the first PTHthat: plates to the first laminate, plates to the second laminate, doesnot plate to the first SPC, and is not continuous from the firstlaminate to the second laminate.

[0012] The present invention provides a method for forming at least onemultisegmented plated through hole (PTH) in a substrate, comprising thesteps of:

[0013] providing a first laminate having a dielectric layer and a secondlaminate having a dielectric layer;

[0014] forming a first selective plate core (SPC) by sandwiching adielectric layer between a first metal layer and a second metal layersuch that the dielectric layer of the first SPC includes a platabledielectric material, forming a hole through the first SPC, and fillingthe hole with a nonplatable dielectric material to form a plug withinthe hole;

[0015] forming the substrate by sandwiching the first SPC between thefirst laminate and the second laminate;

[0016] forming a first through hole through the substrate such that thefirst through hole passes through the plug resulting in a cylindricalsegment of the nonplatable dielectric material circumscribing a portionof the first through hole; and

[0017] metalizing a wall of the first through hole to form a first PTHof the at least one PTH, resulting in a metal plating on the first PTHthat: plates to the first laminate, plates to the second laminate, doesnot plate to the first SPC, and is not continuous from the firstlaminate to the second laminate.

[0018] The present invention provides an electrical structure,comprising:

[0019] a substrate including a first selective plate core (SPC)sandwiched between a first laminate and a second laminate, wherein thefirst laminate includes a dielectric layer, wherein the second laminateincludes a dielectric layer, and wherein the first SPC comprises adielectric layer having a nonplatable dielectric material;

[0020] a first through hole through the substrate, wherein a metalplating on a wall of the first through hole: is plated to the firstlaminate, is plated to the second laminate, is not plated to the firstSPC, and is not continuous from the first laminate to the secondlaminate.

[0021] The present invention provides an electrical stricture,comprising:

[0022] a substrate including a first selective plate core (SPC)sandwiched between a first laminate and a second laminate, wherein thefirst laminate includes a dielectric layer, wherein the second laminateincludes a dielectric layer, wherein the first SPC includes a dielectriclayer having a dielectric material that is platable, wherein the firstSPC further includes a cylindrical segment of a dielectric material thatis nonplatable, and wherein the cylindrical segment extends through atotal thickness of the first SPC; and

[0023] a first through hole through the substrate, wherein thecylindrical segment circumscribes a portion of the first through hole,and wherein a metal plating on a wall of the first through hole: isplated to the first laminate, is plated to the second laminate, is notplated to the first SPC, and is not continuous from the first laminateto the second laminate.

[0024] The present invention provides a method and structure forutilizing a PTH in a substrate in a manner that facilitates an increasedwiring density in the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1 depicts a front cross-sectional view of a selective platecore (SPC) comprising a nonplatable dielectric layer sandwiched betweentwo metal layers, in accordance with embodiments of the presentinvention.

[0026]FIG. 2 depicts FIG. 1 after a hole has been formed through theSPC.

[0027]FIG. 3 depicts FIG. 2 after the hole has been filled with aplatable dielectric material.

[0028]FIG. 4 depicts FIG. 3 after the two metal layers have been removedfrom the SPC.

[0029]FIG. 5 depicts a front cross-sectional view of a substratecomprising a first dielectric laminate, a first SPC, a second dielectriclaminate, a second SPC, and a third dielectric laminate, in accordancewith embodiments of the present invention.

[0030]FIG. 6 depicts an example of the first dielectric laminate of FIG.5.

[0031]FIG. 7 depicts an example of the third dielectric laminate of FIG.5.

[0032]FIG. 8 depicts an example of the second dielectric laminate ofFIG. 5.

[0033]FIG. 9 depicts FIG. 5 after plated through holes through the SPChave been formed.

[0034]FIG. 10 depicts a front cross-sectional view of a selective platecore (SPC) comprising a platable dielectric layer sandwiched between twometal layers, in accordance with embodiments of the present invention.

[0035]FIG. 11 depicts FIG. 10 after a hole has been formed through theSPC.

[0036]FIG. 12 depicts FIG. 11 after the hole has been filled with anonplatable dielectric material.

[0037]FIG. 13 depicts FIG. 12 after the two metal layers have beenremoved from the SPC.

[0038]FIG. 14 depicts a front cross-sectional view of a substratecomprising a first dielectric laminate, a first SPC, a second dielectriclaminate, a second SPC, and a third dielectric, in accordance withembodiments of the present invention.

[0039]FIG. 15 depicts FIG. 14 after plated through holes through the SPChave been formed.

DETAILED DESCRIPTION OF THE INVENTION

[0040] Embodiments of the present invention are disclosed herein. Firstembodiments are depicted in FIGS. 1-9. Second embodiments are depictedin FIGS. 10-15.

[0041] In relation to the first embodiments of the present invention,FIG. 1 illustrates a front cross-sectional view of a selective platecore (SPC) 10 in an initial stage of its formation. The SPC 10 comprisesa nonplatable dielectric layer 12 sandwiched between metal layers 13 and14, in accordance with embodiments of the present invention. The metallayers 13 and 14 may each include, inter alia, copper. The nonplatabledielectric layer 12 includes a nonplatable dielectric material that isnonplatable with respect to a seeding process and an electricallyconductive metal plating process. That is, the nonplatable dielectricmaterial cannot be electroplated by the seeding process followed byelectroplating by the electrically conductive plating process, for anyreason including the following two reasons. The first reason is that thenonplatable dielectric material cannot be seeded with a seeding materialassociated with the seeding process. The second reason is that, althoughthe nonplatable dielectric material can be seeded with the seedingmaterial, the nonplatable dielectric material cannot be electroplatedwith electrically conductive metal plating material of the metal platingprocess following the seeding. The nonplatable dielectric layer 12 mayinclude, inter alia, a prepreg. The nonplatable dielectric material mayinclude, inter alia, a fluoropolymer-glass material, afluoropolymer-ceramic material, a fluorinated epoxy material, a lowsurface energy thermoplastic material such as polyethylene, etc.

[0042]FIG. 2 illustrates FIG. 1 after a hole 16 has been formed throughthe SPC 10. The hole 16 may be formed by any method known to one ofordinary skill in the art such as by, inter alia, laser drilling ormechanical drilling.

[0043]FIG. 3 illustrates FIG. 2 after the hole 16 has been filled withplatable dielectric material to form a plug 18. The platable dielectricmaterial can be electroplated by the process of seeding with the seedingmaterial followed by the process of electroplating with the electricallyconductive metal plating material. The platable dielectric material mayinclude, inter alia, an epoxy resin, polyimide, BT-epoxy, cyanate ester,and other thermoset resins. Any of the aforementioned platabledielectric materials may optionally contain various inorganic or organicparticulate fillers, or fiber reinforcements, etc. As will be seen inthe discussion infra of FIG. 9, a through hole may pass through the plug18. Since the plug 18 includes the platable dielectric material,subsequent seeding and electroplating of the through hole will form anelectrically conductive plating on the platable dielectric material thatexists on the wall of the through hole. In contrast, a seeding andelectroplating of a through hole passing through the nonplatabledielectric layer 12, at a location where there is no plug of platabledielectric material, will not form a conductive plating on thenonplatable dielectric material.

[0044]FIG. 4 illustrates FIG. 3 after the metal layers 13 and 14 havebeen optionally removed from the SPC 10 by any method known to one ofordinary skill in the art such as by, inter alia, chemical etching.While the metal layers 13 and 14 may be removed as shown in FIG. 4, itis also within the scope of the present invention not to remove themetal layers 13 and 14. The metal layers 13 and 14 may provide benefitin some applications. For example, circuit lines may be formed from themetal layers 13 and 14 in some applications but are not shown here inorder to simply illustration.

[0045]FIG. 5 illustrates a front cross-sectional view of a substrate 20comprising, in accordance with embodiments of the present invention, alaminate 22 on a SPC 30, the SPC 30 on a laminate 24, the laminate 24 ona SPC 40, and the SPC 40 on a laminate 26. Thus, the SPC 30 issandwiched between the laminate 22 and the laminate 24. Similarly, theSPC 40 is sandwiched between the laminate 24 and the laminate 26. Thelaminates 22, 24, and 26 are each platable with respect to the seedingprocess and the electrically conductive metal plating process. Thesubstrate may include, inter alia, a printed circuit board (PCB).

[0046] The SPC 30 and the SPC 40 are each of the type shown in FIG. 4.The SPC 30 comprises a nonplatable dielectric layer 32 that includes anonplatable dielectric material and a plug 34 of a platable dielectricmaterial. The SPC 40 comprises a nonplatable dielectric layer 42 thatincludes a nonplatable dielectric material and plugs 44 and 46 each madeof a platable dielectric material. The nonplatable dielectric layers 32and 42 may include, inter alia, a prepreg. The nonplatable dielectricmaterial of the dielectric layers 32 and 42 may each include, interalia, a fluoropolymer-glass material, a fluoropolymer-ceramic material,or other composite materials which exhibit hydrophobicity or low surfaceenergy, etc. The platable dielectric material of the plugs 34, 44, and46 may each include, inter alia, an epoxy resin, or various other filledor unfilled moderate surface energy organic resin or compositematerials, etc. Although the SPC 30 and the SPC 40 do not have metallayers such as the metal layers 13 and 14 of FIG. 3, it is within thescope of the present invention for either or both of the SPC 30 and theSPC 40 to have metal layers such as the metal layers 13 and 14 of FIG.3.

[0047] In FIG. 5, the laminate 22 includes a dielectric layer and mayinclude, inter alia, a prepreg as shown in FIG. 6. In FIG. 6, a laminate23 exemplifies the laminate 22 of FIG. 5. The laminate 23 comprises acore 55 coupled to a prepreg 59. The core 55 includes a prepreg 56sandwiched between metal layers 57 and 58. The metal layers 57 and 58may each include, inter alia, copper. The prepregs 56 and 59 eachinclude a platable dielectric material such as, inter alia, an epoxyresin, or epoxy/glass or various other PCB laminate materials, etc.Noting that the laminate 23 of FIG. 6 represents the laminate 22 of FIG.5, a surface 54 of the prepreg 59 of FIG. 6 is in contact with a surface37 of the SPC 30 of FIG. 5. In typical applications, the prepreg 59 isnot coupled to the core 55 prior to composite lamination of thestructure of the substrate 20 of FIG. 5, but is added the structureduring such composite lamination in order to adhere the core 55 to theSPC 30.

[0048] In FIG. 5, the laminate 26 includes a dielectric layer and mayinclude, inter alia, a prepreg as shown in FIG. 7. In FIG. 7, a laminate27 exemplifies the laminate 26 of FIG. 5. The laminate 27 comprises acore 80 coupled to a prepreg 84. The core 80 includes a prepreg 81sandwiched between metal layers 82 and 83. The metal layers 82 and 83may each include, inter alia, copper. The prepregs 81 and 84 eachinclude a platable dielectric material such as, inter alia, an epoxyresin, polyimide, BT-epoxy, cyanate ester, and other thermoset resins.Any of the aforementioned platable dielectric materials may optionallycontain various inorganic or organic particulate fillers, or fiberreinforcements, etc. If the laminate 27 of FIG. 7 represents thelaminate 26 of FIG. 5, then a surface 86 of the prepreg 84 of FIG. 7 isin contact with a surface 49 of the SPC 40 of FIG. 5.

[0049] In FIG. 5, the laminate 24 includes a dielectric layer and mayinclude, inter alia, a prepreg as shown in FIG. 8. In FIG. 8, thelaminate 25 exemplifies the laminate 24 of FIG. 5. The laminate 25comprises a core 90 sandwiched between a prepreg 94 and a prepreg 95.The core 90 includes a prepreg 91 sandwiched between metal layers 92 and93. The metal layers 92 and 93 may each include, inter alia, copper. Theprepregs 91, 94, and 95 each include a platable dielectric material suchas, inter alia, an epoxy resin, polyimide, BT-epoxy, cyanate ester, andother thermoset resins. Any of the aforementioned platable dielectricmaterials may optionally contain various inorganic or organicparticulate fillers, or fiber reinforcements, etc. If the laminate 25 ofFIG. 8 represents the laminate 24 of FIG. 5, then a surface 96 of thelaminate 25 of FIG. 8 is in contact with the surface 38 of the SPC 30 ofFIG. 5, and the surface 97 of the laminate 25 of FIG. 8 is in contactwith the surface 48 of the SPC 40 of FIG. 5.

[0050]FIG. 9 illustrates FIG. 5 after plated through holes 52, 62, and72 have been formed through the SPC 20. The through hole 52 passesthrough the platable dielectric material of the plugs 34 and 44 (seeFIG. 5) to form cylindrical segments 35 and 45, respectively, of theplatable dielectric material. The through hole 62 passes through thenonplatable dielectric material of the nonplatable dielectric layer 32,and through the platable dielectric material of the plug 46 (see FIG. 5)to form a cylindrical segment 47 of the platable dielectric material.The through hole 72 passes through the nonplatable dielectric materialof the nonplatable dielectric layers 32 and 42, respectively.

[0051] The through holes 52, 62, and 72 are seeded by the seedingprocess and electroplated by the electrically conductive metal platingprocess, in any manner known to one of ordinary skill in the art, toform a plated though hole (PTH) 50, a PTH 60, and a PTH 70,respectively. The PTH 50 comprises a continuous plating 53. Since thecylindrical segments 35 and 45 each include platable dielectricmaterial, the plating 53 plates to the cylindrical segments 35 and 45,and is continuous from the laminate 22 to the laminate 26.

[0052] The PTH 60 comprises a plating segment 64 and a plating segment66. Since the nonplatable dielectric layer 32 includes nonplatabledielectric material, the electrically conductive plating material cannotplate to the nonplatable dielectric layer 32 in the through hole 62.Accordingly, the plating segment 64 is electrically isolated from theplating segment 66, and the plating in the through hole 62 is notcontinuous from the laminate 22 to the laminate 24. Nonetheless, sincethe cylindrical segment 47 includes platable dielectric material, theplating segment 66 plates to the cylindrical segment 47, and iscontinuous from the laminate 24 to the laminate 26.

[0053] The PTH 70 comprises plating segments 74, 76, and 78. Since thenonplatable dielectric layers 32 and 42 each includes nonplatabledielectric material, the electrically conductive plating material cannotplate to the nonplatable dielectric layers 32 and 42 in the through hole72. Accordingly, the plating segment 74 is electrically isolated fromthe plating segment 76, and the plating in the through hole 72 is notcontinuous from the laminate 22 to the laminate 24. Similarly, theplating segment 76 is electrically isolated from the plating segment 78,and the plating in the through hole 72 is not continuous from thelaminate 24 to the laminate 26.

[0054]FIG. 9 also shows lands 201-224. Although not explicitly shown,some or all of the lands 201-224 may be used to facilitate electricalconnections within the substrate 20. As an example, an electricallyconductive coupler 240 (e.g., electrically conductive wiring)electrically couples the land 204 to the land 205. Generally, any landmay be electrically coupled to any other land or internal circuitry inthe substrate 20.

[0055] In relation to the second embodiments of the present invention,FIG. 10 illustrates a front cross-sectional view of a selective platecore (SPC) 110 in an initial stage of its formation. The SPC 110comprises a platable dielectric layer 112 sandwiched between metallayers 113 and 114, in accordance with embodiments of the presentinvention. The metal layers 113 and 114 may each include, inter alia,copper. The platable dielectric layer 112 includes a platable dielectricmaterial that is platable with respect to a seeding material and aelectrically conductive plating material. The platable dielectric layer112 may include, inter alia, a prepreg. The platable dielectric materialmay include, inter alia, an epoxy resin, polyimide, BT-epoxy, cyanateester, and other thermoset resins. Any of the aforementioned platabledielectric materials may optionally contain various inorganic or organicparticulate fillers, or fiber reinforcements, etc.

[0056]FIG. 11 illustrates FIG. 10 after a hole 116 has been formedthrough the SPC 110. The hole 116 may be formed by any method known toone of ordinary skill in the art such as by, inter alia, laser drillingor mechanical drilling.

[0057]FIG. 12 illustrates FIG. 11 after the hole 116 has been filledwith nonplatable dielectric material to form a plug 118. The nonplatabledielectric material is nonplatable with respect to the seeding materialand the electrically conductive plating material. The nonplatabledielectric material may include, inter alia, a fluoropolymer-glassmaterial, a fluoropolymer-ceramic material, a fluorinated epoxymaterial, a low surface energy thermoplastic material such aspolyethylene, etc. As will be seen in the discussion infra of FIG. 15, athrough hole may pass through the plug 118. Since the plug 118 includesthe nonplatable dielectric material, subsequent seeding andelectroplating of the through hole will not form electrically conductiveplating on the nonplatable dielectric material that exists on the wallof the through hole. In contrast, seeding and electroplating of athrough hole passing through the platable dielectric layer 112, at alocation where there is no plug of nonplatable dielectric material, willform electrically conductive plating on the platable dielectric layer112.

[0058]FIG. 13 illustrates FIG. 12 after the metal layers 113 and 114have been optionally removed from the SPC 110 by any method known to oneof ordinary skill in the art such as by, inter alia, chemical etching.While the metal layers 113 and 114 may be removed as shown in FIG. 13,it is also within the scope of the present invention not to remove themetal layers 113 and 114. The metal layers 113 and 114 may providebenefit in some applications. For example, circuit lines may be formedfrom the metal layers 113 and 114 in some applications.

[0059]FIG. 14 illustrates a front cross-sectional view of a substrate120 comprising, in accordance with embodiments of the present invention,a laminate 122 on a SPC 130, the SPC 130 on a laminate 124, the laminate124 on a SPC 140, and the SPC 140 on a laminate 126. Thus, the SPC 130is sandwiched between the laminate 122 and the laminate 124. Similarly,the SPC 140 is sandwiched between the laminate 124 and the laminate 126.The laminates 122, 124, and 126 are each platable with respect to theseeding material and the electrically conductive plating process.

[0060] The SPC 130 and the SPC 140 are each of the type shown in FIG.13. The SPC 130 comprises a platable dielectric layer 132 that includesa platable dielectric material and a plug 134 of a nonplatabledielectric material. The SPC 140 comprises a platable dielectric layer142 that includes a platable dielectric material and plugs 144 and 146each made of a nonplatable dielectric material. The platable dielectriclayers 132 and 142 may include, inter alia, a prepreg. The platabledielectric material of the dielectric layers 132 and 142 may eachinclude, inter alia, an epoxy resin, polyimide, BT-epoxy, cyanate ester,and other thermoset resins. Any of the aforementioned platabledielectric materials may optionally contain various inorganic or organicparticulate fillers, or fiber reinforcements, etc. The nonplatabledielectric material of the plugs 134, 144, and 146 may each include,inter alia, a fluoropolymer-glass material, a fluoropolymer-ceramicmaterial, a fluorinated epoxy material, a low surface energythermoplastic material such as polyethylene, etc. Although the SPC 130and the SPC 140 do not have metal layers such as the metal layers 113and 114 of FIG. 12, it is within the scope of the present invention foreither or both of the SPC 130 and the SPC 140 to have metal layers suchas the metal layers 113 and 114 of FIG. 12.

[0061] In FIG. 14, the laminates 122, 124, and 126 each includes adielectric layer and may include, inter alia, a prepreg. The laminates23, 27, and 25 of FIGS. 6, 7, and 8, respectively, exemplify thelaminates 122, 124, and 126 in the same manner, discussed supra, as thelaminates 23, 27, and 25 exemplify the laminates 22, 24, and 26 of FIG.5. For example, in accordance with the discussion supra in conjunctionwith FIG. 6, the prepreg 59 is not coupled to the core 55 prior tocomposite lamination of the structure of the substrate 120 of FIG. 14,but is added the structure during such composite lamination in order toadhere the core 55 to the SPC 130.

[0062]FIG. 15 illustrates FIG. 14 after plated through holes 172, 162,and 152 have been formed through the SPC 120. The through hole 172passes through the nonplatable dielectric material of the plugs 134 and144 (see FIG. 14) to form cylindrical segments 135 and 145,respectively, of the nonplatable dielectric material. The through hole162 passes through the platable dielectric material of the platabledielectric layer 132, and through the nonplatable dielectric material ofthe plug 146 (see FIG. 14) to form a cylindrical segment 147 of thenonplatable dielectric material. The through hole 172 passes through theplatable dielectric material of the platable dielectric layers 132 and142, respectively.

[0063] The through holes 172, 162, and 152 are each seeded by theseeding process and electroplated by the electrically conductive metalplating process, in any manner known to one of ordinary skill in theart, to form a PTH 170, a PTH 160, and a PTH 150, respectively. The PTH170 comprises plating segments 174 176, and 178. Since the cylindricalsegments 135 and 145 each include nonplatable dielectric material, theelectrically conductive metal plating material cannot plate to thecylindrical segments 135 and 145 in the through hole 172. Accordingly,the plating segment 174 is electrically isolated from the platingsegment 176, and the plating in the through hole 172 is not continuousfrom the laminate 122 to the laminate 124. Similarly, the platingsegment 176 is electrically isolated from the plating segment 178, andthe plating in the through hole 172 is not continuous from the laminate124 to the laminate 126.

[0064] The PTH 160 comprises a plating segment 164 and a plating segment166. Since the platable dielectric layer 132 includes platabledielectric material, the electrically conductive metal plating materialplates to the platable dielectric layer 132 in the through hole 162.Accordingly, the plating segment 164 plates to the platable dielectriclayer 132 and is continuous from the laminate 122 to the laminate 124.Since the cylindrical segment 147 includes nonplatable dielectricmaterial, the electrically conductive plating material does not plate tothe cylindrical segment 147 in the through hole 162. Thus, the platingsegment 164 is electrically isolated from the plating segment 166, andthe plating in the through hole 162 is not continuous from the laminate124 to the laminate 126.

[0065] The PTH 150 comprises a continuous plating 153. Since theplatable dielectric layers 132 and 142 each include platable dielectricmaterial, the plating 153 plates to the platable dielectric layers 132and 142, and is continuous from the laminate 122 to the laminate 126.

[0066]FIG. 15 also shows lands 301-324. Although not explicitly shown,some or all of the lands 301-324 may be used to facilitate electricalconnections within the substrate 20. As an example, an electricallyconductive coupler 340 (e.g., electrically conductive wiring)electrically couples the land 314 to the land 315. Generally, any landmay be electrically coupled to any other land or internal circuitry inthe substrate 120.

[0067] In a substrate having a multisegmented PTH of the presentinvention, each plated segment could be used for a different purpose orfunction. For example, each plated segment could independently connectto wiring within the substrate. Thus, the multisegmented PTH facilitatesa higher wiring density in the substrate.

[0068] The scope of the present invention includes structures withinclude SPC's of the first embodiments (e.g., the SPC's 30 and 40 ofFIG. 9) and SPC's of the second embodiments (e.g., the SPC's 130 and 140of FIG. 15) in the same substrate or composite PCB. The number of SPC'sand laminate layers may differ from what is shown in FIG. 9 and 15.Generally, the substrate or PCB of the present invention includes atleast one SPC such that each SPC is sandwiched between two dielectriclaminates. Additionally, although FIGS. 9 and 15 shows the SPC's 30 and40 in FIG. 9, and the SPC's 130 and 140 in FIG. 15, as beingsymmetrically distributed in a direction 99 within the substrates 20 and120, respectively, generally the SPC cores need not be symmetricallydistributed within a substrate or PCB.

[0069] Furthermore, the electrically conductive metal plating processused in the present invention may include, as an alternative to seedingfollowed by electroplating, an electroless metal deposition stepfollowed by the electroplating. Generally, metalizing a wall meansforming a metal plating on the wall by any process known to one ofordinary skill in the art such as by seeding followed by electroplatingor by electroless metal deposition followed by electroplating or by fullbuild electroless plating. Also definitionally in the context ofmetalizing, a dielectric material that is characterized as nonplatable(or platable) is understood to be nonplatable (or platable) with respectto the metalizing.

[0070] While embodiments of the present invention have been describedherein for purposes of illustration, many modifications and changes willbecome apparent to those skilled in the art. Accordingly, the appendedclaims are intended to encompass all such modifications and changes asfall within the true spirit and scope of this invention.

What is claimed is:
 1. A method for forming at least one multisegmentedplated through hole (PTH) in a substrate, comprising the steps of:providing a first laminate having a dielectric layer and a secondlaminate having a dielectric layer; forming a first selective plate core(SPC) by sandwiching a dielectric layer between a first metal layer anda second metal layer, wherein the dielectric layer of the first SPCincludes a nonplatable dielectric material; forming the substrate bysandwiching the first SPC between the first laminate and the secondlaminate; forming a first through hole through the substrate; andmetalizing a wall of the first through hole to form a first PTH of theat least one PTH, resulting in a metal plating on the first PTH that:plates to the first laminate, plates to the second laminate, does notplate to the first SPC, and is not continuous from the first laminate tothe second laminate.
 2. The method of claim 1, wherein the step offorming a first SPC further comprises forming a hole through the firstSPC and filling the hole with a platable dielectric material to form aplug within the hole, and further comprising: forming a second throughhole through the substrate such that the second through hole passesthrough the plug resulting in a cylindrical segment of the platabledielectric material circumscribing a portion of the second through hole;and metalizing a wall of the second through hole to form a second PTH ofthe at least one PTH, resulting in a metal plating of the second PTHwhich is continuous from the first laminate to the second laminate. 3.The method of claim 1, further comprising providing a third laminatehaving a dielectric layer, and forming a second SPC by: sandwiching adielectric layer between a first metal layer and a second metal layersuch that the dielectric layer of the second SPC includes a nonplatabledielectric material; forming a hole through the second SPC; and fillingthe hole with a platable dielectric material to form a plug within thehole, wherein the step of forming the substrate further comprisessandwiching the second SPC between the second laminate and the thirdlaminate, wherein the first through hole passes through the plugresulting in a cylindrical segment of the platable dielectric materialcircumscribing a portion of the first through hole, and wherein themetal plating is continuous from the second laminate to the thirdlaminate.
 4. The method of claim 1, wherein the step of forming a firstSPC further comprises removing the first metal layer and the secondmetal layer.
 5. The method of claim 1, wherein the step of forming afirst SPC further comprises selectively removing: a portion of the firstmetal layer resulting in a circuitization of the first metal layer, aportion of the second metal layer resulting in a circuitization of thesecond metal layer, or a combination thereof.
 6. The method of claim 1,wherein the first metal layer includes copper, and wherein the secondmetal layer includes copper.
 7. The method of claim 1, wherein thenonplatable dielectric material is selected from the group consisting ofa fluoropolymer-glass material, a fluoropolymer-ceramic material, afluorinated epoxy material, and a low surface energy thermoplasticmaterial.
 8. The method of claim 1, wherein the platable dielectricmaterial is selected from the group consisting of an epoxy resin, apolyimide, a BT-epoxy, a cyanate ester, a thermoset resin, an epoxyresin having an addition, a polyimide having the addition, a BT-epoxyhaving the addition, a cyanate ester having the addition, a thermosetresin having the addition, and combinations thereof, and wherein theaddition is selected from the group consisting of an organic particulatefiller, an inorganic particulate filler, an organic fibrousreinforcement, an inorganic fibrous reinforcement, and combinationsthereof.
 9. A method for forming at least one multisegmented platedthrough hole (PTH) in a substrate, comprising the steps of: providing afirst laminate having a dielectric layer and a second laminate having adielectric layer; forming a first selective plate core (SPC) bysandwiching a dielectric layer between a first metal layer and a secondmetal layer such that the dielectric layer of the first SPC includes aplatable dielectric material, forming a hole through the first SPC, andfilling the hole with a nonplatable dielectric material to form a plugwithin the hole; forming the substrate by sandwiching the first SPCbetween the first laminate and the second laminate; forming a firstthrough hole through the substrate such that the first through holepasses through the plug resulting in a cylindrical segment of thenonplatable dielectric material circumscribing a portion of the firstthrough hole; and metalizing a wall of the first through hole to form afirst PTH of the at least one PTH, resulting in a metal plating on thefirst PTH that: plates to the first laminate, plates to the secondlaminate, does not plate to the first SPC, and is not continuous fromthe first laminate to the second laminate.
 10. The method of claim 9,further comprising: forming a second through hole through the substrate;and metalizing the wall of the second through hole to form a second PTHof the at least one PTH, resulting in a metal plating on the second PTHwhich is continuous from the first laminate to the second laminate. 11.The method of claim 9, further comprising providing a third laminate,and forming a second SPC by: sandwiching a dielectric layer between afirst metal layer and a second metal layer such that the dielectriclayer of the second SPC includes a platable dielectric material, whereinthe step of forming the substrate further comprises sandwiching thesecond SPC between the second laminate and the third laminate, andwherein the step of metalizing the wall results in the metal platingbeing continuous from the second laminate to the third laminate.
 12. Themethod of claim 9, wherein the step of forming a first SPC furthercomprises removing the first metal layer and the second metal layer. 13.The method of claim 9, wherein the step of forming a first SPC furthercomprises selectively removing: a portion of the first metal layerresulting in a circuitization of the first metal layer, a portion of thesecond metal layer resulting in a circuitization of the second metallayer, or a combination thereof.
 14. The method of claim 9, wherein thefirst metal layer includes copper, and wherein the second metal layerincludes copper.
 15. The method of claim 9, wherein the nonplatabledielectric material is selected from the group consisting of afluoropolymer-glass material, a fluoropolymer-ceramic material, afluorinated epoxy material, and a low surface energy thermoplasticmaterial.
 16. The method of claim 9, wherein the platable dielectricmaterial is selected from the group consisting of an epoxy resin, apolyimide, a BT-epoxy, a cyanate ester, a thermoset resin, an epoxyresin having an addition, a polyimide having the addition, a BT-epoxyhaving the addition, a cyanate ester having the addition, a thermosetresin having the addition, and combinations thereof, and wherein theaddition is selected from the group consisting of an organic particulatefiller, an inorganic particulate filler, an organic fibrousreinforcement, an inorganic fibrous reinforcement, and combinationsthereof.
 17. An electrical structure, comprising: a substrate includinga first selective plate core (SPC) sandwiched between a first laminateand a second laminate, wherein the first laminate includes a dielectriclayer, wherein the second laminate includes a dielectric layer, andwherein the first SPC comprises a dielectric layer having a nonplatabledielectric material; a first through hole through the substrate, whereina metal plating on a wall of the first through hole: is plated to thefirst laminate, is plated to the second laminate, is not plated to thefirst SPC, and is not continuous from the first laminate to the secondlaminate.
 18. The electrical structure of claim 17, further comprising asecond through hole through the substrate, wherein the first SPC furthercomprises a cylindrical segment of the platable dielectric material,wherein the cylindrical segment extends through a total thickness of thefirst SPC, wherein the cylindrical segment circumscribes a portion ofthe second through hole, and wherein a metal plating on a wall of thesecond through hole is continuous from the first laminate to the secondlaminate.
 19. The electrical structure of claim 17, wherein thesubstrate further comprises a second SPC and a third laminate, whereinthe second SPC is sandwiched between the second laminate and the thirdlaminate, wherein the second SPC includes a dielectric layer having anonplatable dielectric material, wherein the second SPC furthercomprises a cylindrical segment of the platable dielectric material,wherein the cylindrical segment extends through a total thickness of thesecond SPC, wherein the cylindrical segment circumscribes a portion ofthe second through hole, and wherein the metal plating is continuousfrom the second laminate to the third laminate.
 20. The electricalstructure of claim 17, wherein the first SPC further comprises a firstmetal layer and a second metal layer, and wherein the nonplatabledielectric layer is sandwiched between the first metal layer and thesecond metal layer.
 21. The electrical structure of claim 20, whereinthe first metal layer includes copper, and wherein the second metallayer includes copper.
 22. The electrical structure of claim 17, whereinthe nonplatable dielectric material is selected from the groupconsisting of a fluoropolymer-glass material, a fluoropolymer-ceramicmaterial, a fluorinated epoxy material, and a low surface energythermoplastic material.
 23. The electrical structure of claim 17,wherein the platable dielectric material is selected from the groupconsisting of an epoxy resin, a polyimide, a BT-epoxy, a cyanate ester,a thermoset resin, an epoxy resin having an addition, a polyimide havingthe addition, a BT-epoxy having the addition, a cyanate ester having theaddition, a thermoset resin having the addition, and combinationsthereof, and wherein the addition is selected from the group consistingof an organic particulate filler, an inorganic particulate filler, anorganic fibrous reinforcement, an inorganic fibrous reinforcement, andcombinations thereof.
 24. An electrical structure, comprising: asubstrate including a first selective plate core (SPC) sandwichedbetween a first laminate and a second laminate, wherein the firstlaminate includes a dielectric layer, wherein the second laminateincludes a dielectric layer, wherein the first SPC includes a dielectriclayer having a dielectric material that is platable, wherein the firstSPC further includes a cylindrical segment of a dielectric material thatis nonplatable, and wherein the cylindrical segment extends through atotal thickness of the first SPC; and a first through hole through thesubstrate, wherein the cylindrical segment circumscribes a portion ofthe first through hole, and wherein a metal plating on a wall of thefirst through hole: is plated to the first laminate, is plated to thesecond laminate, is not plated to the first SPC, and is not continuousfrom the first laminate to the second laminate.
 25. The electricalstructure of claim 24, further comprising a second through hole throughthe substrate, wherein a metal plating on a wall of the second throughhole is continuous from the first laminate to the second laminate. 26.The electrical structure of claim 24, further comprising a thirdlaminate and a second SPC, wherein second SPC is sandwiched between thesecond laminate and the third laminate, wherein the second SPC includesa dielectric layer having a platable dielectric material, and whereinthe metal plating is continuous from the second laminate to the thirdlaminate.
 27. The electrical structure of claim 24, wherein the firstSPC further comprises a first metal layer and a second metal layer, andwherein the nonplatable dielectric layer is sandwiched between the firstmetal layer and the second metal layer.
 28. The electrical structure ofclaim 27, wherein the first metal layer includes copper, and wherein thesecond metal layer includes copper.
 29. The electrical structure ofclaim 24, wherein the nonplatable dielectric material is selected fromthe group consisting of a fluoropolymer-glass material, afluoropolymer-ceramic material, a fluorinated epoxy material, and a lowsurface energy thermoplastic material.
 30. The electrical structure ofclaim 24, wherein the platable dielectric material is selected from thegroup consisting of an epoxy resin, a polyimide, a BT-epoxy, a cyanateester, a thermoset resin, an epoxy resin having an addition, a polyimidehaving the addition, a BT-epoxy having the addition, a cyanate esterhaving the addition, a thermoset resin having the addition, andcombinations thereof, and wherein the addition is selected from thegroup consisting of an organic particulate filler, an inorganicparticulate filler, an organic fibrous reinforcement, an inorganicfibrous reinforcement, and combinations thereof.